1. Field of the Invention
The present invention relates to an apparatus for the assisted handling of a load, i.e., to an apparatus used to lift a load and guide it manually within the limits of a preset space, reducing as much as possible the effort required by the operator who performs these maneuvers.
The apparatus according to the present invention is used for example in a station for assembling mechanical components along a mass-production line or at a station for distributing products or semifinished items meant to be sorted toward machines that perform additional processes.
2. Description of the Background Art
An example of a conventional apparatus is given in Italian patent application no. MI95/A000541, which discloses an apparatus comprising: a supporting structure; means for engaging or accommodating the load; at least one motor unit which actuates the winding and unwinding of a flexible element on a pulley or on a drum; one or more sheaves for guiding the flexible traction element, which are arranged between the pulley and the load engagement means; and means for detecting the weight of the load and the force applied thereto in at least one direction of motion. In an embodiment described in the prior patent application, the apparatus is of the overhead type and the means for detecting the weight of the load and the force applied thereto are constituted by a load cell arranged at the free end of the flexible traction element, at the load engagement means.
The load cell is therefore arranged in a position which is particularly exposed to accidental impacts which can compromise its operation.
In this apparatus it is also necessary to install a different load cell according to the maximum intended capacity of each device. In other words, as the number of reevings of the flexible traction element varies, it is necessary to use different load cells, i.e., load cells capable of detecting the load in the preset operating range for which the device is preset during design and manufacture.
As an alternative, in order to adapt this device to greater loads it would be necessary to install a plurality of load cells. This solution, however, is particularly complicated in terms of the control of the motor unit as a function of the signals generated by the different load cells.
It should also be noted that load cells meant to detect loads over different ranges can also significantly differ in their manufacturing technology, in the characteristics of the signal provided in output, in their error tolerances or in other similar characteristics and accordingly require different automatic control circuits.
This contributes to the particularly high manufacturing costs of these devices, especially in terms of stocks of materials, such as load cells and associated electronic control circuits, which must be kept in store in order to allow production of devices meant for different maximum capacities.